Let’s discuss what Nodes, Full Nodes and Master Nodes are:
A node is a device on the blockchain network, which is the essence of the foundation of the blockchain technology. Nodes are often arranged in the structure of trees. Each cryptocurrency has its own nodes, maintaining the transaction records of that specific token.
Nodes replicates and save an identical copy of the distributed ledger (Blockchain are one form of distributed ledger technology. Not all distributed ledgers employ a chain of blocks to provide a secure and valid distributed consensus). Each participant node of the network updates itself independently.
Nodes which are fully verify and meet all the rules(requirements), for example like, Bitcoin are called full nodes. The client also updates the blockchain with block entries and the miner’s confirmations.
A master node can select a node to verify a user’s identity. Persons and businesses can control the master node manually. For the decentralized solution about the identity issue, the master node can vote for a different node if the node doesn't provide good service.
When two or more PCs are connected and share resources without going through a separate server, it is called Peer–to–Peer network (P2P). It can also be called a peer–to–peer network of nodes. A network is the interaction in an ecosystem in which nodes are connected with links.